A kind of a trimming machine for trimming garden trees and plants, namely a hedge trimmer, is known, which trimming machine includes a pair of cutter blades, each cutter blade having a plurality of cutting edges along its longitudinal direction and driven by a rotary power unit so as to allow the pair of the blades to reciprocate in opposite directions relative to each other. Further, a kind of such a trimming machine is known, which trimming machine uses an eccentric cylindrical cam eccentrically rotated by the rotary power unit in combination with a connecting rod having a larger end part slidably fitted around the eccentric cam in order to convert a rotational motion of the rotary power unit into a reciprocating motion of the pair of the cutter blades. Such a trimming machine is disclosed, for example, in FIG. 9 in the Japanese Patent Publication No. 2966382 to Kramer et al.
When such a conventional trimming machine is worked for a long time, wear may be caused between the larger end part of the connecting rod and the eccentric cam. The trimming machine disclosed in the Kramer et al. has a grease reservoir between the larger end part and the eccentric cam, which grease reservoir makes a certain effect of reducing a frictional force between contact surfaces of the larger end part and the eccentric cam due to lubrication therebetween. However, since an active force itself causing such a friction force is not reduced regardless of the lubrication and the reservoir cannot be a useful means for equalizing an uneven distribution of the frictional force associated with the rotation of the eccentric cam, a need for reducing wear caused between the larger end part of the connecting rod and the eccentric cam still exists.
Thus, an object of the present invention is to provide a trimming machine in which wear caused between the larger end part of the connecting rod and the eccentric cam can be reduced.